MPC555CME Freescale Semiconductor, MPC555CME Datasheet - Page 179

• Manufacturer Part Number: MPC555CME
• Description: KIT EVALUATION FOR MPC555
• Manufacturer: Freescale Semiconductor
• Type: Microcontrollerr

Specifications of MPC555CME

• Contents: Module Board, Installation Guide, Power Supply, Cable, Software and more
• Processor To Be Evaluated: MPC555
• Data Bus Width: 32 bit
• Interface Type: RS-232
• For Use With/related Products: MPC555
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

4.3 Instruction VocabularyBased Compression Model Main Principles
4.3.1 Compression Model Features
MPC555
USER’S MANUAL
The IMPU has the following features:
• Two operation modes are available: “Decompression ON” and “Decompression
• Four regions in which the base address and size can be programmed.
• Region sizes of four Kbytes up to four Gbytes (in powers of two) can be pro-
• Overlap between regions is allowed.
• Each of the four regions supports the following attributes:
• Global region entry declares the default access protection and guarded attributes
• Interrupt generated upon access violation or fetch from guarded region.
• MPC555 / MPC556 MSR[IR] bit controls MPU protection.
• Programming is done using MPC555 / MPC556 mtspr/mfspr instructions to/from
• Designed for minimum power consumption.
• Compressed/non-compressed region with enable/disable option.
• Special reset exception vector for “Decompression ON” mode.
• Implemented for PowerPC architecture
• Up to 30% code size reduction
• No need for address translation tables
• No changes in the CPU architecture
• Compression is done off line by a special “compressor” tool, using a fixed vocab-
• Decompression is done at run-time with special hardware.
• Optimized for cache-less systems:
• Switch between compressed and non-compressed user application sections is
/
OFF”. Switch between compressed and non-compressed user application soft-
ware parts is possible.
grammed. (A region must start on the specified region size boundary.)
for all memory areas not covered by the four regions:
implementation specific special purpose registers.
ulary instruction based algorithm, optimized for the PowerPC instruction set.
possible. (Compressed subroutine can call non-compressed one and be called
from non-compressed portion of user application)
— Minimal performance penalty due to change of program flow execution
— Access protection (use r/ supervisor fetch or no access).
— Guarded attribute (causes an interrupt in case of fetch try).
— On / off option
— Compressed / non-compressed.
— Highly effective in system solutions for low cache-hit ratio environment and for
— Deterministic program execution time
— No performance penalty during sequential program flow execution
— Minimal performance penalty due to change of program flow execution
MPC556
systems with fast embedded program memory
Rev. 15 October 2000
BURST BUFFER
MOTOROLA
4-3